gpio: gpio-xilinx: Add clock support

Adds clock support to the Xilinx GPIO driver.

Signed-off-by: Srinivas Neeli <srinivas.neeli@xilinx.com>
Acked-by: Michal Simek <michal.simek@xilinx.com>
Link: https://lore.kernel.org/r/1605201148-4508-4-git-send-email-srinivas.neeli@xilinx.com
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

diff --git a/drivers/gpio/gpio-xilinx.c b/drivers/gpio/gpio-xilinx.c
index a28aa5b..5327457 100644 (file)
--- a/drivers/gpio/gpio-xilinx.c
+++ b/drivers/gpio/gpio-xilinx.c
@@ -6,6 +6,7 @@
  */
 
 #include <linux/bitops.h>
+#include <linux/clk.h>
 #include <linux/errno.h>
 #include <linux/gpio/driver.h>
 #include <linux/init.h>
@@ -38,6 +39,7 @@
  * @gpio_state: GPIO state shadow register
  * @gpio_dir: GPIO direction shadow register
  * @gpio_lock: Lock used for synchronization
+ * @clk: clock resource for this driver
  */
 struct xgpio_instance {
        struct gpio_chip gc;
@@ -46,6 +48,7 @@ struct xgpio_instance {
        u32 gpio_state[2];
        u32 gpio_dir[2];
        spinlock_t gpio_lock[2];
+       struct clk *clk;
 };
 
 static inline int xgpio_index(struct xgpio_instance *chip, int gpio)
@@ -334,11 +337,25 @@ static int xgpio_probe(struct platform_device *pdev)
                return PTR_ERR(chip->regs);
        }
 
+       chip->clk = devm_clk_get_optional(&pdev->dev, NULL);
+       if (IS_ERR(chip->clk)) {
+               if (PTR_ERR(chip->clk) != -EPROBE_DEFER)
+                       dev_dbg(&pdev->dev, "Input clock not found\n");
+               return PTR_ERR(chip->clk);
+       }
+
+       status = clk_prepare_enable(chip->clk);
+       if (status < 0) {
+               dev_err(&pdev->dev, "Failed to prepare clk\n");
+               return status;
+       }
+
        xgpio_save_regs(chip);
 
        status = devm_gpiochip_add_data(&pdev->dev, &chip->gc, chip);
        if (status) {
                dev_err(&pdev->dev, "failed to add GPIO chip\n");
+               clk_disable_unprepare(chip->clk);
                return status;
        }